The year is 1934, and disgraced federal agent Nathan Devereaux is escorting convicted felon John Banks to visit his dying mother. Banks is despondent, miserably ill with a heavy cold, and unenthusiastic about traveling by plane. It isn't a responsibility Devereaux wants, but something about the prisoner's plight resonates with him. Devereaux charters a plane to Wisconsin, hoping to get there before Banks's mother breathes her last. But a routine journey swiftly turns into a sojourn in hell when a violent winter storm forces the plane miles off course, and Banks's seemingly bad cold turns out to be diphtheria. Stranded many miles from the destination, Devereaux must find a way to save Banks's life without compromising the mission. Like Banks, Devereaux has secrets of his own, and the scope and purpose of his mission don't quite square with the stories he tells. Making matters worse, he is the only one standing between Banks and certain death, but even a federal agent can do only so much--especially an agent with blood on his hands.